With the explosion in the growth of Internet usage among both businesses and households, telephone companies have been pressured to provide affordable, high bandwidth access that will support high-speed multimedia services, such as video on demand, high speed Internet access, and video conferencing. To meet this demand, telephone companies are increasingly turning to xDSL technology. The xDSL technology, while having several different embodiments, can provide throughput rates over 100 times faster than that available through traditional 56 kbps modems.
The following are some of the xDSL technologies that are either available today or are currently being tested on a trial basis: Asymmetric Digital Subscriber Line (ADSL), which has a throughput of 32 kbps to 8.192 Mbps downstream to the customer and 32 kbps to 1.088 Mbps upstream to the network; Rate Adaptive Asymmetric Digital Subscriber Line (RADSL), which is a rate adaptive variation of ADSL; High-bit-rate Digital Subscriber Line (HDSL), which offers full duplex throughput at T1 (1.544 Mbps) or E1 (2.048 Mbps) data rates; Symmetric Digital Subscriber Line (SDSL), which provides bi-directional throughput at data rates ranging from 160 Kbps–2.084 Mbps; and Very high-bit-rate Digital Subscriber Line (VDSL), which provides high data rates for customers close to the central office (e.g., 51 Mbps for subscribers within 1000 feet). But most importantly, xDSL technologies offer these high data rates over a standard copper telephone line.
In order for a remote DSL modem to function properly, it is necessary for it to conduct a training session, or to train-up, with a central DSL modem. Training-up is a technique for adjusting modem settings based on current telephone line conditions and involves the transmission of a special training sequence to a remote modem. Upon receiving the special training sequence, the remote modem calculates the distortion effects of the subscriber line and compensates accordingly for line conditions. If a train-up is unsuccessful, the endpoint customer has practically no means of knowing why the modem is not working. As a result, a communications service provider often finds it necessary to send a technician to the customer's premises in order to determine the cause of the problem.
Sending a technician to a customer's premises is often referred to as a “truck roll.” Communications service providers strive to reduce the number of truck rolls because there are significant costs associated with them. These costs may involve, for example, maintaining trucks, technicians, handheld test equipment, etc. Furthermore, truck rolls can be time consuming and may therefore be inconvenient for customers who will experience an interruption in DSL services while the cause of the problem is being diagnosed. Therefore, there exists a need for a faster and more efficient system and method for determining the cause of a communication problem in a DSL communication system.